--- title: "Google Calendar Not Syncing With Outlook: Causes & Fixes" description: "Google Calendar not syncing with Outlook? It is usually a one-way ICS feed that refreshes slowly. 6 causes with exact fixes, plus real two-way sync options." url: https://www.virtosoftware.com/events/google-calendar-not-syncing-with-outlook/ language: en-US last_modified: 2026-09-25T00:00:00+02:00 translations: de: https://www.virtosoftware.com/de/events/google-calendar-not-syncing-with-outlook/index.md --- # Google Calendar Not Syncing With Outlook: Causes & Fixes [by Kristina Mel](https://www.virtosoftware.com/author/kristina-mel/) Published: Jul 1, 2026 Latest update: Sep 25, 2026 Reading Time: 11 mins [Event Management](https://www.virtosoftware.com/events/) [Microsoft 365](https://www.virtosoftware.com/microsoft-365-guides/) > **Quick answer:** Google Calendar usually fails to sync with Outlook because the connection is a **one-way ICS subscription** (not true two-way sync), the **refresh interval is slow** (Outlook may only poll every few hours), or **account permissions / sharing settings changed**. > > Fast fixes: confirm the calendar is shared correctly in Google, wait out or force the refresh, clear the Outlook cache, and if it’s still stuck, **remove and re-add** the calendar. For real two-way sync, use a connector or an overlay app. Google Calendar and Microsoft Outlook are the two calendars most people juggle at once — Outlook anchored in the Microsoft 365 workplace, Google Calendar handling personal and cross-platform scheduling. When the two stay in step, planning is effortless. When they drift apart, you get missed meetings, [scheduling conflicts](https://www.virtosoftware.com/events/scheduling-conflicts-guide/), and duplicated events. This 2026 guide covers both sides of the problem: how to **connect Google Calendar and Outlook** in the first place, and how to **fix a sync that has stopped working**. You’ll also see where a purpose-built overlay tool like the [Virto Calendar App for Microsoft 365](https://www.virtosoftware.com/microsoft-365/virto-calendar-overlay-app/) removes the sync headache entirely. ## How to sync Google Calendar with Outlook (and vice versa) If your goal is simply to see your Google Calendar inside Outlook (or the reverse), you don’t need a sync failure to fix — you need the connection set up correctly. Native integration between the two is done through an **ICS/iCal subscription link**. This is a **one-way, read-only** feed: events flow from the source calendar into the destination, but edits made on the destination side don’t flow back. For true two-way sync, jump to the *third-party section* below. > **How to sync Google Calendar with Outlook (fastest method):** > > 1. In Google Calendar, open **Settings → Settings for my calendars**, pick the calendar, and copy the **Secret address in iCal format** under **Integrate calendar**. > 2. In Outlook on the web, click **Add calendar → Subscribe from web**, paste the iCal link, name it, and click **Import**. > 3. In classic Outlook desktop, right-click **Other calendars → Add calendar → From Internet**, paste the link, and confirm. ### Add Google Calendar to Outlook #### Outlook on the web (recommended) - In Google Calendar, click the gear icon → **Settings**. - Choose **Settings for my calendars** and select the calendar you want. - Scroll to **Integrate calendar** and copy the **Secret address in iCal format**. ![Copying the secret iCal address from Google Calendar settings](https://www.virtosoftware.com/images/uploads/2026/07/google-calendar-ical-secret-address.webp) *Pic. 1. Copying the secret iCal address from Google Calendar settings.* - In Outlook.com or your work OWA, open **Calendar** and click **Add calendar**. ![Adding a calendar in Outlook on the web](https://www.virtosoftware.com/images/uploads/2026/07/outlook-web-add-calendar-panel.webp) *Pic. 2. Adding a calendar in Outlook on the web.* - Select **Subscribe from web**, paste the iCal link, set a name and colour, then click **Import**. ![Subscribing to the Google Calendar iCal feed from the web in OWA](https://www.virtosoftware.com/images/uploads/2026/07/owa-subscribe-google-calendar-feed.webp) *Pic. 3. Subscribing to the Google Calendar iCal feed from the web in OWA.* ![The subscribed Google Calendar now appears in the OWA calendar list](https://www.virtosoftware.com/images/uploads/2026/07/owa-google-calendar-subscribed-list.webp) *Pic. 4. The subscribed Google Calendar now appears in the OWA calendar list.* #### Classic Outlook desktop 1. Copy the iCal (secret) address from Google Calendar as above. 2. In classic Outlook, go to **Calendar** view, right-click **Other Calendars**, and choose **Add Calendar → From Internet**. 3. Paste the link, click **OK**, name the calendar, and confirm. Note: the **new Outlook for Windows** and Outlook for Mac add internet calendars in a similar way — look for **Add calendar → Subscribe from web**, the same flow as OWA. Microsoft has been converging the new Outlook and web experiences, so the desktop “From Internet” wording mainly applies to *classic* Outlook. #### Google Workspace users (two-way option) If you’re on a Google Workspace account, you can install **Google Workspace Sync for Microsoft Outlook (GWSMO)** instead of an ICS subscription. It provides a fuller two-way profile between Google and classic desktop Outlook. Download GWSMO, run the setup wizard, sign in with your Workspace address, grant permissions, and choose your sync options. #### Mobile (Outlook app) - Open the Outlook mobile app and tap the **Settings** icon. - Tap **Add account → Add Google Account** (Outlook connects the whole Google account, including calendar). - Complete Google authentication and make sure **calendar sync** is enabled for the account. *After signing in, make sure the Google calendar is actually showing: open the **Calendar** tab, tap the calendars/filter icon, and confirm your Google account’s calendar is checked. If it’s missing, the toggle is usually at the phone level, not in Outlook — on **Android**, go to **Settings → Accounts → \[Google account\] → Account sync → Calendar** (enabled) and grant Outlook calendar permission under **Settings → Apps → Outlook → Permissions**; on **iPhone**, check **Settings → Calendar → Accounts → \[Google\] → Calendars** (on) and **Settings → Outlook → Calendars** (allowed). If it still doesn’t appear, remove and re-add the account and let the initial sync finish.* ![Adding a Google account and enabling calendar sync in Outlook mobile](https://www.virtosoftware.com/images/uploads/2026/07/outlook-mobile-google-account-sync.webp) *Pic. 5. Adding a Google account and enabling calendar sync in Outlook mobile.* ### Add Outlook calendar to Google The reverse direction also uses a published ICS link. #### From Outlook on the web 1. In OWA, open **Settings → Calendar → Shared calendars**. 2. Under **Publish a calendar**, pick the calendar, choose **Can view all details**, and click **Publish**. ![Publishing an Outlook calendar and copying its ICS link](https://www.virtosoftware.com/images/uploads/2026/07/outlook-owa-publish-calendar-ics.webp) *Pic. 6. Publishing an Outlook calendar and copying its ICS link.* 3. Copy the **ICS** link provided. 4. In Google Calendar, click **\+ (Add other calendars) → From URL**, paste the ICS link, and click **Add calendar**. ![Adding the published Outlook calendar to Google Calendar via From URL](https://www.virtosoftware.com/images/uploads/2026/07/google-calendar-add-from-url.webp) *Pic. 7. Adding the published Outlook calendar to Google Calendar via From URL.* To import a fixed snapshot instead of a live feed, export an **.ics** file from Outlook (**File → Save Calendar** in classic desktop, or **Export** in OWA) and use **Import & export** in Google Calendar. ## Common causes & fixes If the calendars are already connected but not staying in sync, work through the causes below from most to least common. ### 1\. It’s a one-way, read-only subscription (by design) The single biggest source of confusion: an ICS subscription is **read-only**. Events created in the source calendar appear in the destination, but anything you add or edit on the destination side will *not* push back. If you expected changes to flow both ways, that’s not a bug — you need a two-way connector (see below) rather than a plain subscription. ### 2\. Slow refresh interval Outlook doesn’t poll subscribed ICS feeds in real time. Depending on the platform and the calendar publisher, updates can lag from **several minutes to several hours**. New events therefore look “missing” when they simply haven’t been fetched yet. Give it time, or force a manual refresh: right-click the calendar in Outlook and choose **Update Calendar / Sync**. ![Forcing a manual calendar refresh in Outlook](https://www.virtosoftware.com/images/uploads/2026/07/outlook-manual-calendar-refresh.webp) *Pic. 8. Forcing a manual calendar refresh in Outlook.* ### 3\. Account, sharing and permission issues Sync will silently fail if the source calendar isn’t shared the way the subscription expects. In Google Calendar, open **Settings for my calendars**, select the calendar, and check **Access permissions** and **Share with specific people or groups**. For a public subscription link, availability must be set appropriately; for corporate Google Workspace, your IT administrator may need to grant access. Also confirm you’re signed into *both* services with the correct accounts, and that no firewall or device-management policy is blocking the feed. ![Checking access permissions and sharing settings in Google Calendar](https://www.virtosoftware.com/images/uploads/2026/07/google-calendar-access-permissions.webp) *Pic. 9. Checking access permissions and sharing settings in Google Calendar.* ### 4\. ICS / iCal link problems A broken or stale iCal address is a frequent culprit. If events stopped updating, the secret address may have been **reset** in Google Calendar — regenerating it invalidates old subscriptions. Re-copy the current **Secret address in iCal format** and re-subscribe. Also verify you’re visiting [calendar.google.com/calendar/syncselect](https://calendar.google.com/calendar/syncselect) to confirm the right calendars are enabled for sync. ### 5\. Cache and stale local data Outlook keeps a local copy of calendar data. When that cache corrupts, sync stalls. Clearing it usually helps: - **Classic desktop:** close Outlook fully, then rename (don’t delete) the **.ost** / **.pst** data file so Outlook rebuilds it on restart. Microsoft’s own guidance covers [clearing the Outlook cache on Windows](https://answers.microsoft.com/en-us/outlook_com/forum/all/clear-the-cache-on-outlook/cde542ba-ed31-4c6b-8317-7889aadc14a5), the [new Outlook for Windows](https://learn.microsoft.com/en-us/answers/questions/1666730/how-to-manually-delete-the-cache-when-using-the-ne), and [Outlook for Mac](https://support.microsoft.com/en-us/outlook/clear-the-cache-in-outlook-for-mac). - **Outlook on the web:** clear the browser cache, sign out fully, close all windows, then sign back in. - **Outlook mobile:** remove the account, clear the app cache (Android) or delete and reinstall the app (iOS), then re-add the account and let the initial sync finish. After clearing cache, the first sync takes longer than usual while Outlook rebuilds its store — don’t interrupt it. ### 6\. Outdated software or conflicting add-ins Version mismatches and third-party add-ins can quietly break sync. Update Outlook (**File → Office Account → About Outlook** to check the version), keep the mobile apps and OS current, and if problems started recently, launch Outlook in **Safe Mode** to test without add-ins. Disable suspect COM add-ins via **File → Options → Add-ins** and re-test. ### Known native-integration limits Some behaviours aren’t fixable because they’re limitations of the Google-to-Microsoft connection, documented in [Microsoft’s known-issues article](https://support.microsoft.com/en-US/Support/known-issues/known-issues-syncing-google-accounts-to-the-microsoft-cloud). The most impactful ones: | Area | Limitation | Workaround | | --- | --- | --- | | Visibility | Events default to “Public” in Outlook; Google privacy doesn’t carry over | Set sensitive events to private manually | | Attachments | Meeting attachments don’t sync between platforms | Share files via cloud links instead | | Deletions | Deleting a meeting auto-notifies the organizer | No silent-delete option; manage etiquette accordingly | | Shared limit | Max of 20 shared calendars can sync | Consolidate calendars where possible | | Free/Busy | Free & Busy permission sharing may not work | Use alternative availability checks | | Responses | Invitations need “Automatically add invitations” enabled in Google | Set it to Yes in Google Calendar settings | *Fig. 1. Key native Google ↔ Outlook sync limitations and workarounds.* ## Two-way / automated sync (third-party) When you need genuine two-way sync — edits flowing both directions, near real-time, without the ICS read-only ceiling — a dedicated tool is the reliable answer. Common options: - **Outlook Google Calendar Sync (OGCS)** — a free, open-source GitHub project (active since 2012) that many users rely on for two-way sync between classic Outlook and Google. - **Commercial connectors** such as [CalendarBridge](https://calendarbridge.com/), [SyncGene](https://www.syncgene.com/), [Cronofy](https://www.cronofy.com/developer/calendar-api), and [Sync2](https://www.sync2.com/) — paid, with more control over direction, fields, and intervals. - **Overlay apps** like the Virto Calendar App, which show all your sources together in one M365 view (covered next). ### Security considerations Before granting any third-party tool access to calendar data, review its **data-privacy** practices, the **scope of permissions** it requests (favour least-privilege), its **enterprise compliance** posture, its **authentication** support (modern auth / MFA), and **where your calendar data is stored and processed**. In regulated environments, run a proper security assessment first. ## Keep calendars unified with Virto Rather than forcing Google and Outlook to sync perfectly, the [Virto Calendar App for Microsoft 365 / SharePoint](https://www.virtosoftware.com/microsoft-365/virto-calendar-overlay-app/) lets you **overlay Google and Outlook calendars in a single view** — plus Exchange Online, SharePoint lists, meeting rooms, and any iCal source — so there’s nothing to break in the first place. ![Example Virto Calendar overlay combining multiple sources in one view](https://www.virtosoftware.com/images/uploads/2026/07/virto-calendar-overlay-multiple-sources.webp) *Pic. 10. Example Virto Calendar overlay combining multiple sources in one view.* Key capabilities: - Overlay multiple calendar sources (Google, Outlook/Exchange, SharePoint, iCal) in one place, with no 20-calendar ceiling. - Support for Exchange Online, SharePoint list integration, and [meeting-room management](https://www.virtosoftware.com/use-cases/rooms-equipment-calendar/). - [Colour-coding](https://www.virtosoftware.com/tasks/why-you-need-to-color-code-your-calendar/) and multiple views to organise event types at a glance. - [Microsoft Teams integration](https://www.virtosoftware.com/microsoft-teams/virto-calendar-app/) and Microsoft Planner task integration for a unified workspace. Because it’s native to Microsoft 365, it keeps the familiar interface, respects enterprise security policies, and works consistently across desktop and mobile. It costs **$2,412 per 100 users per year** with a 3-year agreement (100 users and up), with a **30-day free trial**; smaller teams can use [Virto Shared Calendar](https://www.virtosoftware.com/microsoft-teams/virto-teams-shared-calendar/), which has a free plan. [Schedule a quick demo](https://virtosoftware.pipedrive.com/scheduler/82Q9zOt0/book-a-meeting?utm_source=article_sharepoint_limitations_guide&utm_medium=banner&utm_campaign=cta_stuck_with_setup) · [Start a free 30-day trial](https://appsource.microsoft.com/en-us/product/office/WA200005908) ## FAQ ### Can Google Calendar sync with Outlook? Yes. You can subscribe Outlook to your Google Calendar’s iCal address for a **one-way, read-only** feed, or use a connector/overlay app for two-way sync. Google Workspace users can also install GWSMO for a fuller two-way profile in classic desktop Outlook. ### How do I sync Google Calendar with Outlook? Copy the **Secret address in iCal format** from Google Calendar (**Settings → Settings for my calendars → Integrate calendar**), then in Outlook on the web choose **Add calendar → Subscribe from web** and paste it (or, in classic desktop Outlook, **Other Calendars → Add Calendar → From Internet**). ### Why is my sync one-way / read-only? Because native ICS/iCal subscriptions are read-only by design — the destination calendar only displays events from the source. For edits to flow both ways, use a two-way connector such as OGCS or a commercial sync tool, or unify everything with an overlay app. ### Why is my Google Calendar not updating in Outlook? Usually a slow refresh interval, a reset iCal link, changed permissions, or a stale cache. Force a manual sync, re-copy the current secret address, confirm sharing settings, and clear the Outlook cache if needed. ## Conclusion Keeping Google Calendar and Outlook aligned comes down to two things: setting up the connection correctly (an iCal subscription for one-way, a connector for two-way), and knowing the handful of causes — refresh lag, permissions, stale links, cache, add-ins — behind a sync that stops working. Work through those in order and most problems resolve quickly. If you’d rather not fight native sync at all, an overlay approach like the [Virto Calendar App](https://www.virtosoftware.com/microsoft-365/virto-calendar-overlay-app/) brings every calendar into one Microsoft 365 view — no ICS ceiling, no one-way surprises. For related setups, see our guides on [managing multiple M365 calendars](https://www.virtosoftware.com/events/managing-multiple-m365-calendars/), [syncing Microsoft Teams calendar with Google Calendar](https://www.virtosoftware.com/events/sync-microsoft-teams-calendar-with-google-calendar/), [Teams calendar not syncing with Outlook](https://www.virtosoftware.com/events/teams-calendar-not-syncing-with-outlook/), and the broader [Outlook calendar not syncing](https://www.virtosoftware.com/events/outlook-calendar-not-syncing/) hub. [Kristina Mel](https://www.virtosoftware.com/author/kristina-mel/)